Exploring the scope of poly(ethylene glycol) (PEG) as a soluble polymer matrix for the Stille cross-coupling reaction.
Exploring the scope of poly(ethylene glycol) (PEG) as a soluble polymer matrix for the Stille cross-coupling reaction.
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探索聚乙二醇 (PEG) 作为 Stille 交叉偶联反应的可溶性聚合物基质的范围。
DOI：
10.1021/cc990052o
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Janda,KD
中科院分区：
文献类型：
--
作者：
Sieber,F;WentworthJr,P;Janda,KD
通过首次报道的聚乙二醇负载的钯催化Stille方法，对联芳基、杂芳基和苯乙烯基衍生物库的优化和高效平行合成和纯化进行了描述。初步研究了单甲氧基聚乙二醇5000负载碘与三丁基苯基tin2之间的反应，结果表明，最佳的“液相”条件是PdCl2(PPh3)2（0.1当量）与LiCl（10当量）在DMF中在80℃下催化48 h （20 mM浓度的1a）或24 h （10 mM浓度的1a）。可溶性聚合物负载反应优于溶液相反应，因为三丁基锡副产物和多余的试剂很容易从产物中间分离出来，3沉淀到乙醚中，然后通过bbb99 %的过滤回收聚合物。此外，均偶联副产物6也在此沉淀步骤中被去除。在此条件下，酯交换的联芳基加合物的收率可达97 ~ 98%。在优化的条件下，用peg支持的亲电带（三丁基锡2和7 - 13）平行探索了该反应的范围。随后通过酯交换和短柱层析对聚合物支撑的加合物进行裂解，得到取代苯甲酸酯库，收率（69−99%）和纯度（>95%）高。
The optimization and efficient parallel synthesis and purification of a library of biaryl, heterobiaryl, and styryl derivatives, via the first reported poly(ethylene glycol)-supported palladium-catalyzed Stille procedure, are described. Preliminary investigations into the reaction between monomethoxy poly(ethylene glycol)5000-supported iodide1awith tributylphenyltin2revealed that the optimal “liquid-phase” conditions employ PdCl2(PPh3)2(0.1 equiv) catalysis with LiCl (10 equiv) in DMF at 80 °C for either 48 h (at 20 mM concentration of1a) or 24 h (at 10 mM concentration of1a). The soluble polymer-supported reaction is superior to its solution-phase counterpart because the tributyltin side products and excess reagents are easily separated from the product intermediate3aby precipitation of3ainto diethyl ether followed by recovery of the polymer by filtration in >99%. In addition, the homocoupled byproduct6is also removed during this precipitation step. Under these conditions the transesterified biaryl adduct4acan be isolated in 97−98% yield. The scope of this reaction was probed in a parallel format with the PEG-supported electrophiles1a−band a range of tributyl stannanes2and7−13under the optimized conditions vide supra. Subsequent cleavage of the polymer-supported adducts, by transesterification, and short column chromatography yielded a library of substituted methyl benzoates4a−band14a−bto20a−bin high yield (69−99%) and purity (>95%).